title: Structure of a bifunctional alcohol dehydrogenase involved in bioethanol generation in Geobacillus thermoglucosidasius.
abstract: Bifunctional alcohol/aldehyde dehydrogenase (ADHE) enzymes are found within many fermentative microorganisms. They catalyse the conversion of an acyl-coenzyme A to an alcohol via an aldehyde intermediate; this is coupled to the oxidation of two NADH molecules to maintain the NAD(+) pool during fermentative metabolism. The structure of the alcohol dehydrogenase (ADH) domain of an ADHE protein from the ethanol-producing thermophile Geobacillus thermoglucosidasius has been determined to 2.5 Å resolution. This is the first structure to be reported for such a domain. In silico modelling has been carried out to generate a homology model of the aldehyde dehydrogenase domain, and this was subsequently docked with the ADH-domain structure to model the structure of the complete ADHE protein. This model suggests, for the first time, a structural mechanism for the formation of the large multimeric assemblies or `spirosomes' that are observed for this ADHE protein and which have previously been reported for ADHEs from other organisms.
authors.affiliation: Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, England.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Extance
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Crennell
authors.forename: Kirstin
authors.initials: K
authors.lastname: Eley
authors.forename: Roger
authors.initials: R
authors.lastname: Cripps
authors.forename: David W
authors.initials: DW
authors.lastname: Hough
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Danson
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D056804:Biofuels / Q000382:microbiology*; D018360:Crystallography, X-Ray; D000431:Ethanol; D005285:Fermentation; D056506:Geobacillus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics
chemical_list: D056804:Biofuels; D009097:Multienzyme Complexes; D000431:Ethanol; D000426:Alcohol Dehydrogenase
keywords: ADH domain; ADHE; Geobacillus thermoglucosidasius; bioethanol